This invention relates to power transmission control mechanisms and more particularly to control mechanisms for friction drive transmissions.
Prior art transmission control mechanisms for friction drive transmissions have used a friction ring as a driving connection between the input and output members. Many of these controls provide for moving the friction ring laterally along the friction surfaces to change the speed ratio between the input and output members. Such controls require substantial control forces to move the friction ring during the ratio change. At least one prior art mechanism, which uses a friction ring as a ratio control member, provides a contoured cross section for the ring which when tilted relative to the friction driving members, eliminates the drive connection therebetween such that lateral movement can be accomplished with a low force input. However, during a ratio change with such a device, the driving connection between the input and output members is disconnected.